Means for producing heat-transfer conduits



26, 1930; A; E. HARNSBERGER I 1,774,231

MEANS FOR PRODUCING HEAT TRANSFER CONDUITS Filed Sept. 20, 1927 A. .5?1222772515 aye)" Patented Aug 26, 1930 UNITED- STATES PATENT OFFICE,"

AUDLEY E. HARNSIBERGER, or CHICAGO, ILLINOIS, ASSIGNQR T rm: PURE OILcom- 1 PANY, or CHICAGO, ILLINOIS, A CORPORATION or 01110 MEANS FORPRODUCING HEAT-TRANSFER CONDUITS Application filed September 20, 1927.Serial No. 220,770.

' means of which themetal between the collars will be displaced andcrowded into engagement with the collars so as to firmly retain thelatter in the desired spaced positions'upon the conduit.

For a further understanding of the invention reference is to be had tothe following description and the accompanying drawing, wherein:

Figure 1 is a vertical longitudinal sectional view taken through a heattransfer conduit formed in accordance with the present invention andillustrating the apparatus employed in carrying out the invention,

Figure 2 is a vertical transverse sectional view on the line 22 ofFigure 1,

Figure 3 is a side elevation of the displacing head.

Referring more particularly to the draw ings the numeral 1 designatesgenerally the improved extended surface tube or conduit formedinaccordance with the present invention. This conduit has application invarious heat exchange equipment involving transfer of heat from a gas,vapor or liquid on the outside of the tubeto a gas, vapor or liquid inthe interior of the tube. The tube may be formed from any suitable metalsuch as steel, brass or any suitable alloy, depending upon the servicefor which the tube-is to be employed. Arranged on the tube atlongitudinally spaced intervals are rings or collars 2, which are ofsuitable dimensions and arranged in predetermined spaced relationship,the internal diameter of said collars being just suflicient to allow thesame to be slipped on the outer surfaces of the tube body 3. The body isthen mounted on a lathe bed or other similar machine with the lead screw4 of such machine disposed axially within the tube body. clampedrigidly, and the lead screw 4 is suit ably connected to the lathe chuckor face plate (not shown).

An expander 5 is then drawn through the tube by the rotation of thescrew 4. This expander, in a simple form of the invention, consists of ahead 6, provided with a plurality of radially extending arms 7, to whichare pivoted as at 8 a plurality of longitudinally extending swingingframes 9. These frames are provided with recesses for the reception ofaxles 10 provided in connection with hardened steel rollers 11, whichengage with the inner surfaces of the tube body 3. The operatingposition of the rollers 11 or the frames 9 are controlled-by the mediumof set screws 12, the latter being providedwith heads 13, and the innerends of said screws are set to bear upon the head 6 of the expander.Lock nuts 14 engage with said screws to insure the retention thereof inadjusted posi tions.

It will be seen that the steel rollers 11 may be said to bear againstthe inner wall of the tube body, displacing the metal of the latter byforcing it outwardly into the rings or collars 2, thereby forming slightundulations as indicated on the interior and exterior-of. the conduit,causing said tubes between said collars to possess a greater diameterthan the internal diameter of the collars. By this construction andoperation the rings or collars 2 are firmly united with the conduit body'3 to produce a fixed, unitary construction wherein relative movementbetween the rings or collars and the conduit body iseffectivelyprecluded;

The tube is then,

The expander, having been drawn through the tube body, is shifted inposition to an extent equivalent to the Width of one-0f the rollers 11and then a ain forced or drawn through the bod T 's process is repeateduntil the desire expansion is obtained. It is obvious that in place ofthe adjusting screws 12 a wedge shaped collar could be forced underneaththe swinging frames 9, thereby securing uniform adjustment of all therollers.

- Other'modific'ations of the specific type of expander disclosed may beutilized without departing from the. spirit of the invention. Forexample, the expander .has, been shown as provided with four rollers.This number may be doubled if desired or two or more expanders may beutilized at the same time with their rollers spaced equidistantly aroundthe interior of the tube. Of course, the interior of a conduit so formedwill not be smooth, but in the majority of heat transfer operations thisshould 7 not prove objectionable.

stood that the rings or collars may. be of a different material than thetube. body, for

example, the utilizin of rings having a lower coefiicient of expans1onthan the tube body itself, so as to prevent loosening of the rings It isalso under plurality of arms having certain of their ends pivotallyconnected with said head and extending substantially parallel with saidscrew, rollers mounted upon the intermediate portions of said arms, andthreaded adjusting devices carried by the outer or free ends of saidarms and engageablewith said hub to'control the radial swinging movementof said arms with respect to said head.

In testimony whereof I aflix my signature.

'AUDLEY E. HARNSBERGER.

under extremely high temperature conditions.

-What is claimed is:

1. An expanding tool comprising a longitudinally extending screwarranged to be positioned axially within a tube, a head formed toinclude a hub internally threaded to receive the screw, a plurality ofradially swing ing arms pivotally mounted at one end upon said head andlying in planes substantially parallel with said screw, rollers mountedfor rotation on said arms and rotatable about axes arranged transverselyto the axis of the screw, andmeans carried by the outer ends of saidarms and engageable with said hub for controlling the radial adjustmentof the arms and the rollers carried thereby, whereby said rollers may becrowded into contact with the inner peripheral walls of the tube inwhich 15 the same is positioned.

2. .An expanding tool comprising a head, means for moving said headlongitudinally through a tube, a pluralit of relatively .sw'inging armshaving certain-of their ends pivotally connected with said head, saidarms being disposed generally in planes 'substan-.

tially parallel to the longitudinal axis of a co-operating tube, rollerscarried by the intermediate portions of said arms and turnable aboutaxes disposed transversely of the arms,

and adjusting devices carried by'the outer or free ends of said arms andco-operative with said head for, controlling the radial swingingmovement of said arms and the no rollers carried thereby with respect tosaid head. 3. An expanding tool comprising a longitudinally extendingscrew, a head having a hub internally threaded to receive the screw androtatable about the axis of the screw. a

i so

